Range of motion (or ROM), is the distance (linear or angular) that a movable object may normally travel while properly attached to another. It is also called range of travel, particularly when talking about mechanical devices and in mechanical engineering fields. For example, a volume knob (a rotary fader) may have a 300 range of travel from the "off" or muted (fully attenuated) position at lower left, going clockwise to its maximum-loudness position at lower right. As used in the biomedical and weightlifting communities, range of motion refers to the distance and direction a joint can move between the flexed position and the elongated position. The act of attempting to increase this distance through therapeutic exercises (range of motion therapystretching from flexion to extension for physiological profit) is also sometimes called range of motion.